Synnefo

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from sqlalchemy import Table, Column, MetaData

from sqlalchemy.types import BigInteger

from sqlalchemy.sql import select

from sqlalchemy.exc import NoSuchTableError

from dbworker import DBWorker

def create_tables(engine):

    metadata = MetaData()

    columns = []

    columns.append(Column('serial', BigInteger, primary_key=True))

    Table('qh_serials', metadata, *columns, mysql_engine='InnoDB')

    metadata.create_all(engine)

    return metadata.sorted_tables

class QuotaholderSerial(DBWorker):

    """QuotaholderSerial keeps track of quota holder serials.

    """

    def __init__(self, **params):

        DBWorker.__init__(self, **params)

        try:

            metadata = MetaData(self.engine)

            self.qh_serials = Table('qh_serials', metadata, autoload=True)

        except NoSuchTableError:

            tables = create_tables(self.engine)

            map(lambda t: self.__setattr__(t.name, t), tables)

    def get_lower(self, serial):

        """Return entries lower than serial."""

        s = select([self.qh_serials.c.serial])

        s = s.where(self.qh_serials.c.serial < serial)

        r = self.conn.execute(s)

        rows = r.fetchall()

        r.close()

        return rows

    def lookup(self, serials):

        """Return the registered serials."""

        if not serials:

            return []

        s = select([self.qh_serials.c.serial])

        s = s.where(self.qh_serials.c.serial.in_(serials))

        r = self.conn.execute(s)

        rows = r.fetchall()

        r.close()

        return [row[0] for row in rows]

    def insert_serial(self, serial):

        """Insert a serial.

        """

        s = self.qh_serials.insert()

        r = self.conn.execute(s, serial=serial)

        r.close()

    def insert_many(self, serials):

        """Insert multiple serials.

        """

        r = self.conn.execute(

            self.qh_serials.insert(),

            list({'serial':s} for s in serials)

        )

        r.close()

    def delete_many(self, serials):

        if not serials:

            return

        st = self.qh_serials.delete().where(

            self.qh_serials.c.serial.in_(serials)

        )

        self.conn.execute(st).close()